FIG. 10 is a circuit diagram showing an electronic door system in a vehicle in a related art. The electronic door system of FIG. 10 shows an example of a vehicle having four doors. Door ECUs (Electronic Control Unit) 200a to 200d are respectively mounted on doors. The four door ECUs 200a to 200d are connected together by a LAN (Local Area Network) (main bus) communicated by a protocol such as a CAN (Controller Area Network) or a BEAN (Body Electronics Area Network) or the like.
The right front door ECU 200a controls a right front outer (remote control) mirror module 264a disposed in the door, a right front door lock module 274a, a right front power window module 284a, a right front power window switch module 244a, a right front curtsy lamp 254a and a curtsy lamp switch 294a disposed in the vehicle. The right rear door has the same structure as that of the right front door except the outer mirror module 264a. The structures of the left front door and the left rear door have the same structures as those of the right front and right rear doors. In the vehicle, an outer (remote control) mirror switch 214 is further provided and connected to a vehicle body ECU 210.
Load driving parts for driving motors or heaters in auxiliary equipment modules 264 to 284 such as outer mirror modules 264, door lock modules 274, etc. and sensors or switches and I/O parts for inputting/outputting signals in the auxiliary equipment modules 264 to 284 are contained in the door ECUs 200. The load driving parts and the I/O parts are connected to each of electrical parts in the auxiliary equipment modules 264 to 284 by wire harnesses. Further, the door ECU 200 includes a centralized control part for controlling the auxiliary equipment modules 264 to 284 connected thereto and a communication part for communicating with other ECUs. Accordingly, when the outer mirror switch 214 is turned ON/OFF, the vehicle body ECU 210 transmits a control signal from the communication part incorporated therein to the right front and left front doors ECU 200a and ECU 200c. The doors ECU 200a and ECU 200c decode the control signal in the centralized control parts incorporated therein and instruct the load driving parts of the outer mirror modules 264a and 264c contained therein to operate outer mirrors.
As the related art which is related to the present invention, the applicant of the present invention discloses in JP-A-2001-287605 a wire harness connected to a LAN for an option that even when the form of a vehicle is different, a basic main controller can be made common and a cost can be reduced. In the Patent Document 1, electrical parts for a vehicle are controlled through a gate wire harness from a sub ECU.
A usual electronic door system for a vehicle has such problems as described below. Firstly, when the specifications and functions of electrical load parts related to a door change, a wire harness connected to each ECU needs to be changed. Thus, the kinds and product numbers of wire harnesses are undesirably increased.
Secondly, when the functions of the electrical load parts related to the door increase, the number of circuits is increased and the wire harnesses are enlarged. As a result, a mass is undesirably increased.
Thirdly, owing to the centralized control by the ECUs, the increase of the functions of the electrical load parts related to the door undesirably causes the ECUs to be enlarged, the mass to be increased (the deterioration of a fuel efficiency and a traveling performance) and loading characteristics to be deteriorated. Further, software with which the ECUs are loaded is enlarged and the product numbers of the ECUs are increased. Consequently, the number of development processes is inconveniently increased and the number of specification adding and changing processes is undesirably increased.